title: Core body temperature in obesity.
abstract: BACKGROUND
  A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity.
  
  
  OBJECTIVE
  We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals.
  
  
  METHODS
  In study 1, nonobese [body mass index (BMI; in kg/m(2)) <30] and obese (BMI ≥30) adults swallowed wireless core temperature-sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18-25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis.
  
  
  RESULTS
  Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P < 0.0001).
  
  
  CONCLUSIONS
  Obesity is not generally associated with a reduced core body temperature. It may be necessary to study individuals with function-altering mutations in core temperature-regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500.
authors.affiliation: Unit on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD 20892-1103, USA.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Heikens
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Gorbach
authors.forename: Henry S
authors.initials: HS
authors.lastname: Eden
authors.forename: David M
authors.initials: DM
authors.lastname: Savastano
authors.forename: Kong Y
authors.initials: KY
authors.lastname: Chen
authors.forename: Monica C
authors.initials: MC
authors.lastname: Skarulis
authors.forename: Jack A
authors.initials: JA
authors.lastname: Yanovski
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001831:Body Temperature; D001833:Body Temperature Regulation; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009765:Obesity / Q000503:physiopathology*; D012727:Sex Characteristics